Gillian Guy, chief executive of Citizens Advice, the statutory consumer champion for energy, said EDF Energy’s move will “come as another blow to its loyal customers”.

“People on EDF’s standard variable tariffs are already feeling the effects of an electricity price rise that came into force last month, a fresh price hike of £78 a year will hit those already struggling,” she said.

In a statement about its decision EDF Energy committed to offer vulnerable customers affected by its price hike a £100 rebate.

Guy welcomed this news but said that more “action is urgently needed across the industry to protect the poorest households from repeated price hikes”.

One way of doing this would be to extend the cap on energy prices for prepayment meter customers, suggested Guy.

“Extending the prepayment meter cap to credit meter customers eligible for the Warm Homes Discount would guarantee protection for millions of the poorest families and pensioners.”